Solar arrays can provide energy to pump water to watering troughs for cows, improving water quality on remote pastures and saving money too. Farmers can more sustainably manage their pastures if cows are not all clustered around small creeks, eroding the banks.
One example of a worst case scenario is Dick Lester’s Spring Valley Ranch in Cherokee County, Iowa. He had one tiny creek that his cattle were trampling to death, reducing their own water supply.
He needed to pump water 150 feet up the hill to three separate watering troughs so the cows would spread out and not trample the creek’s stream banks, fouling their own drinking water supply and reducing the flow by eroding the stream banks.
Dewey Stouffer, of Little Sioux Prairie Company, installed Lester’s solar powered livestock watering system. A mere 1.4 KW system supplies all the energy it needs (average homes need from 2KW to 8KW). A gravel trench drains part of the creek 15 feet underground, to a pump. Then the solar array provides the energy to move the water up 150 feet, going through 4,600 feet of pipe to three separate drinking troughs for the cows.
Water levels in the tanks signal the pump to add water. “When there is demand for water, a valve opens, and the pressure tank supplies water until the pressure is gone,” Stouffer says . “Then it pumps nine gallons of water per minute up the hill until the tank shuts off. The system will pressurize again and shut off.”
Although this is a truly off-grid solar system; not connected to the electric power lines, there are no batteries needed for storage. The energy is stored in the holding tanks of water. When its sunny out, the water tanks fill to the top. And cows need more water on hot days. “We’re storing water in the big water tanks rather than storing electricity in batteries,” is how the solar installer puts it.
Because the cattle have access to the three huge watering troughs dispersed to the edges of the property up the hill, they stay away from the creek; cutting down on stream bank erosion.The banks are no longer bare, because they have access to other water. As a result, now stream banks along the creek are healing with signs of reduced erosion and vegetative growth, which means cleaner water with less sediment buildup.
In Iowa a typical solar pumped livestock watering system will cost $5,000-$7,000, depending on the type of pump, number of water tanks, feet of pipe, number of solar panels and the hours of labor needed for hire. The size of pump and number of solar panels you need depends on the number of cattle, water source, amount of lift and how far water needs to be pumped. Iowa’s local NRCS field offices have demonstrations available.
Lester chose this freestanding battery-less solar system for under $7,000 rather than run an electric line to the remote pasture to pumping power because it would have cost over $20,000 to run a line out a mile off the road. But there was more.
“Once you’ve installed the system, that’s the end of it,” Lester says. “I like the idea of solar power and not depending on electricity from the grid to run it,” He was impressed by how quickly grass returned to the stream banks since installing the new solar watering system. “Anybody can see that it’s way better for the land,”
Source: Iowa NRCS USDA